James a



(No Model.)

J. A. LAKIN.

AUDIPHONE.

Patented Aug. 20, 1895.

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/W A 6% i ilnrrnn Sunrise JAMES A. LAKIN, OF WESTFIELD, MASSACHUSETTS.

AUDiPHQNE.

SIEGHICATION forming port of Letters Patent No. 54.4,?32, dated August 20, 1895..

Application filed October 25, 1894. Serial No. 526,921. (No modem,

To all whom it may concern.-

Be it known that I, JAMES A. LAKIN, a citizen of the United Statesoit' America, residing at Westfield, in the county of l-Iampden and State of Massachusetts, have invented new and usefullmprovements in Audiphones, of which the following is a specification.

This invention relates to improvements in audlphones or sound-amplifying devices for the deaf, the object being to produce a de vice which shall be very efficient in its sound intensifying action, taking the place of an car-trumpet, and one which shall be of very small size'and not at all conspicuous in use, and moreover shallbe simple, practicable, and cheap of construction.

The audiphoneot this invention essentially comprises a hollow shell or casing the head or forward end of which is composed of a vibratory diaphragmmhile the rear extremity thereof is of a contracted tubular form endwise open, asecond diaphragm located within an intermediate portion of the casing, and a connection which engages and extends from one to the other of the diaphragms.

In the accompanying drawings, in which this invention?- is illustrated, Figure l is a central longitudinal section of the andiphone. Fig. 2 is a side View, and Fig. 3 is a. front view, of the same.

In the drawings, A represents the case or shell of the instrument, of which the forward portion die the larger, and is of bowl or forwardly-flaring form, While the rear portion is composed of the contracted tubular portion or stem 17, which is endwise open.

The head of the instrument is composed of a vibratorydiaphragm d, of any suitable material, as thin celluloid, rubber, metal, or thin wood, and it has its circular edge seated in the rabbetf and there held by the conlining-ring g, which is held in place by shellac or other suitable adhesive.

Between the forward. end and the rear end of the instrument-thnt is, atnportlon within the casing which is in practice of considerably less diameter than that closed by the I forward dlnphragm-lsn second diaphragm h,

which has its position as a partition across the casing and which diaphragm is suitably edgewise supported, as by resting under and against the overhanging flange or ledge l'. have found it much preferable to have I 'the rear diaphragm, which is the nearer the ear, the smaller, substantially as shown, the result or". which is that the sound transmitted from the larger to the smaller diaphragm is much simplified and intensified.

Both diaphraglns have a connection the one with the other through the medium of the ligament m, which may be silk cord or other suitable like connectionywhich has each end knotted to lie by such knotted portion, respectively, against the forward and rear faces of the diaphragms d h, the knots beinglarger than the perforations which are centrally formed in the diaphragins. The length of the silk cord or other connection is such as to cause, when the cord is perfectly taut, a

drawing of the central portions of the dia' phragms slightly toward each other, as indicated in the drawings, thereby rendering them more sensitive to the vibratory effect of the sound, and the seatsfand j prevent the diaphragms from unduly approaching each other.

The tubular stem is of such. attenuated size extraneous sounds into the ear independently of those transmitted through theaudiphone, as well as a-frictional engagementforth'e re tention of the instrument in the car without requiring a continued hand pressure or support, the end. portion of the stem is covered with the sleeve 72, of soft rubberor analogous material.

The instrument is preferably constructed with its hollow portion to the rear of the innor diaphragm turned more or less angular to the axis of the forward part of the case, whereby while the stem may enter the ear laterally the bodyof the audiphone willhave relatively to the stem a forward inclination, to more properly and directly receive the sound.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is

1. An audiphone comprising a case, thewise open, and adapted for insertion into the passage of the ear, a second diaphragm located within an intermediate portion of, and as a partition across the casing, and a ligament which engages and extends from one to the otherotsaid diaphragnis,substantially as described.

2. An audiphone comprising a case, the head or forward end of which is composed of wvihratory diaphragm, and the rear end of which is of a contracted tnbniar form, end- 'wis-o open, and? adapted for insertion into the passage of the ear, a aecond diaphragm lo cated within an intermediate portion of, and as a partition across the case which is of less diameter than the forward diaphragm, and'a ligament which engages and extends from one to the other of said diaphraglns,substantially as described;

J AM ES A. LAKIN. 

